Gold Chapter (855 KB) - Ministry of Mines and Energy

Mineral Resources of Namibia Precious Metals - Gold
3.3.3.2.2 Thorn Tree Mine, Okamuvia 144
Located within the old Snyman’s claims on
Okamuvia 144, 60 km northwest of Windhoek,
the Thorn Tree Mine was worked for its copper
content before 1914 and sporadically in the
1950s and 1960s. A hydrothermal, brecciated
quartz vein crosscutting quartz-biotite schist
contains minor gold (Burg, 1942). See copper
chapter for more detail.
3.3.3.2.3 Ganams 316 Occurrence
On the northern part of the farm Ganams
316, 90 km west of Windhoek, gold and copper
are associated with a quartz vein, traceable over
a strike length of 700 m. Discovered by a
geochemical soil sampling survey, the
composite samples taken about 100 m apart
assayed between 0.2 g/t and 4.3 g/t gold (Scott,
1975).
3.4 Okahandja Lineament Zone
3.4.1.1.1 Rüdenau Nord 6
Drilling of a sulphidic quartz-biotite schist on
the farm Rüdenau Nord 6, 25 km southwest of
Okahandja just north of the Okahandja
Lineament, proved the metasomatic deposit to
be stratabound and auriferous with sample
maximum values of 2.95 g/t and 6.15 g/t gold
being obtained (Marsh, 1988). See also copper
chapter.
3.5 Southern Central Zone
3.5.1 Nosib Group
3.5.1.1 Etusis Formation
3.5.1.1.1 Sphinx Mine, Nordenburg 76
Gold is associated with chalcocite-rich
hydrothermal quartz veins in amphibolite facies
meta-arkose at the Sphinx mine, 40 km southsouthwest
of Usakos (Smith, 1965; Anon,
1967). Soil sampling produced a maximum
4.1 - 18
concentration of 565 ppb gold (Landmark G.,
1987b), while a grab sample contained 0.35 g/t
gold (Steven et al., 1994).
Rock sampling of quartz blows on
Nordenburg 76 gave average assay values of
less than 10 ppb gold with an anomaly of 99 ppb
gold (Du Plessis and Clynch, 1968; Landmark
G., 1987b).
3.5.1.1.2 Bergrus 94 Copper Occurrence
Gold is recorded in deep-level hydrothermal
chalcocite- and malachite-bearing quartz
veining in quartzite on the farm Bergrus 94, 40
km south-southwest of Usakos (Miller, 1983a).
Mineralisation is associated with local shearing
parallel to bedding and is truncated on one side
against a granitic intrusion. Stream-sediment
sampling over the occurrence revealed
concentrations of 21 ppb gold (Landmark G.,
1987c). However, follow-up work failed to
confirm this.
3.5.1.1.3 Anomalies
Regional exploration sampling by Anglo
American Prospecting Services produced
anomalous assay values on farms 40 km southsouthwest
of Usakos. Follow-up work failed to
locate any mineralisation. See Table 4.
3.5.1.2 Khan Formation - Tinkas Member
3.5.1.2.1 Gamikaubmund Mine, Ukuib 84
Situated directly east of the confluence of the
Gamikaub and Swakop rivers, 47 km southsoutheast
of Usakos, the defunct mine in the
past exploited on a small scale tectonically
controlled quartz veins in fold hinges. Gold
mineralisation is confined to calc-silicate
horizons in a sequence of monotonous
metaclastic rocks. Recent sampling of the old
workings showed that the veining contains
between 0.25 g/t and 1.79 g/t gold (Dekker,
1983; Esterhuizen, 1984; De Greef, 1988a).